Many systems can receive an input supply voltage from a power supply, for example, to power electronic circuits or devices in the systems. Since some of these systems can include electronic circuits or devices, such as touch screen displays, which perform operations in response to signals with a voltage level that differs from that of the input supply voltage, the systems can include charge pumps or other voltage altering device to boost or lower the voltage level of the input supply voltage.
Charge pumps typically alter an input supply voltage by an integer multiple of the voltage level of the input supply voltage. The charge pumps can operate efficiently when configured to receive a specific input supply voltage and output a specific output signal. Any change in the input supply voltage provided to the charge pumps or in a desired output signal can cause the charge pumps to perform inefficiently with a high output impedance, which can alter the voltage and current levels of the output signal. Thus, developers of electronic devices that include charge pumps either tailor a design of the charge pumps to a specific customer system or provide a charge pump with a universal design that may operate inefficiently in the customer system.